Guiding introducer system for use in medical procedures in the left ventricle

ABSTRACT

A guiding introducer system for use in the treatment of arrhythmia associated with the left ventricle from the ventricular side comprising an inner guiding introducer and an outer guiding introducer wherein the inner guiding introducer is comprised of a first and second section and the outer guiding introducer is comprised of a first and second sections. The guiding introducer system is for use in sensing, pacing, and ablating procedures in the left ventricle.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. applicationSer. No. 09/728,961 titled “Guiding Introducer System for Use in MedicalProcedures in the Left Ventricle,” filed on Dec. 4, 2000; which is acontinuation of application Ser. No. 09/160,406 titled “GuidingIntroducer System for Use in Medical Procedures in the Left Ventricle,”filed on Sep. 25, 1998 and issued on Dec. 5, 2000 as U.S. Pat. No.6,156,018; which is continuation of application Ser. No. 08/661,094titled “Guiding Introducer System for Use in Medical Procedures in theLeft Ventricle,” filed on Jun. 10, 1996 and issued on Sep. 29, 1998 asU.S. Pat. No. 5,814,029; which is a continuation-in-part of applicationSer. No. 08/388,800 titled “Guiding Introducers for Use in the Treatmentof Accessory Pathways around the Mitral Valve using the RetrogradeApproach,” filed on Feb. 14, 1995 and issued on Jun. 24, 1997 as U.S.Pat. No. 5,640,955, and a continuation-in-part of application Ser. No.08/389,252 titled “Guiding Introducers for use in the Treatment of LeftVentricular Tachycardia,” filed on Feb. 16, 1995 and issued on Mar. 3,1998 as U.S. Pat. No. 5,772,400, and a continuation-in-part ofapplication Ser. No. 08/333,791 titled “Method for Mapping and/orAblation of Anomalous Conduction Pathways,” filed Nov. 3, 1994 andissued on Oct. 15, 1996 as U.S. Pat. No. 5,564,440, and acontinuation-in-part of application Ser. No. 08/333,759 titled “GuidingIntroducer System for Use in the Right Atrium,” filed on Nov. 3, 1994and issued on May 13, 1997 as U.S. Pat. No. 5,628,316; the disclosure ofeach of the above-referenced related applications and patents are herebyincorporated be reference in their entirety as thou fully set forthherein. This application is also related to U.S. Pat. Nos. 5,497,774 and5,427,119, the disclosures of which are hereby incorporated by referencein their entirety as though fully set forth herein.

BACKGROUND OF INVENTION

[0002] 1. Field of Invention

[0003] This invention relates to sheaths or introducers. Moreparticularly, this invention relates a guiding introducer system formapping and ablation procedures in the left ventricle of the humanheart.

[0004] 2. Prior Art

[0005] Introducers and catheters have been in use for medical proceduresfor many years. For example, catheters have been used to convey anelectrical stimulus to a selected location within the human body.Another use is monitoring and making measurements for diagnostic testswithin the human body. Catheters are also used by physicians to examine,diagnose and treat while positioned at a specific location within thebody which is otherwise inaccessible without more invasive procedures.In use, catheters are inserted into a major vein or artery which is nearthe body surface. These catheters are then guided to the specificlocation for examination, diagnosis or treatment by manipulating thecatheter through the artery or vein of the human body.

[0006] Catheters have become increasingly useful in remote and difficultto reach locations within the body. However, the utilization of thesecatheters is frequently limited because of the need for the preciseplacement of the electrodes of the catheter at a specific locationwithin the body.

[0007] Control of the movement of catheters to achieve such preciseplacement is difficult because of the inherent structure of a catheter.The body of a conventional catheter is long and tubular. To providesufficient control of the movement of the catheter, it is necessary thatits structure be somewhat rigid. However, the catheter must not be sorigid as to prevent the bending or curving necessary for movementthrough the vein, artery or other body part to arrive at the specifiedlocation. Further, the catheter must not be so rigid as to cause damageto the artery or vein while it is being moved within the body.

[0008] While it is important that the catheter not be so rigid as tocause injury, it is also important that there be sufficient rigidity inthe catheter to accommodate torque control, i.e., the ability totransmit a twisting force along the length of the catheter. Sufficienttorque control enables controlled maneuverability of the catheter by theapplication of a twisting force at the proximal end of the catheter thatis transmitted along the catheter to its distal end. The need forgreater torque control often conflicts with the need for reducedrigidity to prevent injury to the body vessel.

[0009] Catheters are used increasingly for medical procedures involvingthe human heart. In these procedures a catheter is typically advanced tothe heart through veins or arteries and then is positioned at aspecified location within the heart. Typically, the catheter is insertedin an artery or vein in the leg, neck, upper chest or arm of the patientand threaded, generally with the aid of a guidewire and conventionalintroducer, through various arteries or veins until the tip of thecatheter reaches the desired location in the heart.

[0010] The distal end of a catheter used in such a procedure issometimes preformed into a desired curvature so that by torquing thecatheter about its longitudinal axis, the catheter can be manipulated tothe desired location within the heart or in the arteries or veinsassociated with the heart. For example, U.S. Pat. No. 4,882,777discloses a catheter with a complex curvature at its distal end for usein a specific procedure in the right ventricle of a human heart. U.S.Pat. No. 5,231,994 discloses a guide catheter for guiding a ballooncatheter for the dilation of coronary arteries. U.S. Pat. No. 4,117,836discloses a catheter for the selective coronary angiography of the leftcoronary artery and U.S. Pat. Nos. 5,299,574 5,215,540, 5,016,640 and4,883,058 disclose catheters for selective coronary angiography of theright coronary artery.

[0011] Conventionally, angiographic or balloon catheters are guided tothe particular location within the heart, such as the coronary arteries,by use of a guidewire. During this procedure, the guidewire is firstintroduced into the vein or artery and is then advanced through thevasculature to the particular coronary artery to be analyzed. Thecatheter is then directed over the guidewire to the particular coronaryartery. A conventional short straight introducer is often used to assistin introducing the coronary catheter into the vasculature, but is notused for advancing the coronary catheter through the vasculature to thecoronary artery.

[0012] U.S. Pat. No. 5,242,441 discloses a deflectable catheter forablation procedures in the ventricular chamber. See also U.S. Pat. No.4,033,331. In addition, U.S. Pat. No. 4,898,591 discloses a catheterwith inner and outer layers containing braided portions. The '591 patentalso discloses a number of different curvatures for intravascularcatheters.

[0013] Thus, catheters with predetermined shapes, designed for useduring specific medical procedures generally associated with the heartor the vascular system have been disclosed.

[0014] In addition to single catheters with various curvatures, U.S.Pat. No. 4,581,017 discloses an inner and outer guide catheter, numbers138 and 132, for use with a balloon catheter for treatment of coronaryarteries. U.S. Pat. No. 5,120,323 discloses a guide catheter system foruse in coronary arteries comprising an outer guide catheter (12) and atelescoping guide catheter (26), neither of which are precurved. U.S.Pat. No. 5,267,982 discloses a catheter assembly and methods forcatheterization of coronary arteries wherein an inner catheter (50) andouter catheter (52) are used in combination for the treatment of rightand left coronary angiographic procedures. See also U.S. Pat. No.4,935,017 which discloses a similar device. U.S. Pat. No. 5,290,229discloses a straight outer sheath and a preformed inner catheter for usein the heart. See also U.S. Pat. Nos. 5,304,131, 4,810,244 and5,279,546.

[0015] U.S. Pat. No. 5,476,495 discloses a shaped guide sheath (166) foruse in the right ventricle for ablation procedures.

[0016] Ablation procedures in the heart using a single, straight guidesheath have been disclosed. For example, catheter ablation of accessorypathways using a long vascular sheath by means of a transseptal orretrograde approach is discussed in Saul, J. P., et al. “CatheterAblation of Accessory Atrioventricular Pathways in Young Patients: Useof long vascular sheaths, the transseptal approach and a retrograde leftposterior parallel approach” J. Amer. Coll. Card., Vol. 21, no. 3, pps571-583 (Mar. 1, 1993). See also Swartz, J. F. “RadiofrequencyEndocardial Catheter Ablation of Accessory Atrioventricular PathwayAtrial Insertion Sites” Circulation, Vol. 87, no. 2, pps. 487-499(February, 1993).

[0017] In addition, U.S. Pat. No. 5,427,119 discloses a shaped guidingintroducer for introduction of an ablation and mapping catheter into theright atrium for the treatment of specific cardiac arrhythmia. U.S. Pat.No. 5,497,774 discloses the use of a guiding introducer for introductionof an ablation and mapping catheter into the left atrium for thetreatment of specific cardiac arrhythmia.

[0018] U.S. Pat. No. 4,641,649 discloses the use of high frequencyenergy for the treatment of tachycardia or cardiac dysrhythmia. See alsoU.S. Pat. Nos. 5,246,438 and 4,945,912, which disclose the use of radiofrequency energy for ablation of cardiac tissue. In addition, variousarticles have disclosed the ablation of specific locations within theheart by use of energy, in particular, radio frequency energy. See, forexample, Gallagher, J. J. et al. “Catheter Technique for Closed-ChestAblation of the Atrioventricular Conduction System” N. Engl. J. Med.Vol. 306, pp. 194-200 (1982); Horowitz, L. N. “Current Management ofArrhythmia” pp. 373-378 (1991); Falk, R. H. et al. “Atrial FibrillationMechanics and Management” pp. 359-374 (1992); and Singer, I. “ClinicalManual of Electrophysiology” pp. 421-431 (1993).

[0019] In addition, U.S. Pat. No. 5,172,699 discloses a general processfor the identification and ablation of ventricular tachycardia sites.See also U.S. Pat. Nos. 5,222,501 and 5,242,441.

[0020] In addition, the use of radio frequency ablation energy for thetreatment of Wolff-Parkinson-White Syndrome in the left atrium by use ofa transseptal sheath is disclosed in Swartz, J. F. et al.“Radiofrequency Endocardial Catheter Ablation of AccessoryAtrioventricular Pathway Atrial Insertion Sites” Circulation 87:487-499(1993). See also Tracey, C. N. “Radio Frequency Catheter Ablation ofEctopic Atrial Tachycardia Using Paced Activation Sequence Mapping” J.Am. Coll. Cardiol. 21:910-917 (1993).

[0021] While a number of references have disclosed ablation proceduresin the heart utilizing sheaths and catheters, there is still a need fornew methods for the introduction of ablation catheters to specificlocations in the heart, including specifically the left ventricle.

[0022] Accordingly, it is an object of this invention to disclose aguiding introducer system for selected medical procedures associatedwith the left ventricle of the human heart.

[0023] It is a further object of this invention to disclose a guidingintroducer system for use in selected electrophysiology proceduresassociated with the left ventricle of the human heart.

[0024] Another object of this invention is to disclose a guidingintroducer system for use in selected ablation procedures associatedwith the left ventricle of the heart.

[0025] It is a still further object of this invention to disclose aguiding introducer system for use in the selected ablation of sitesassociated with the mitral valve from the ventricular side for thetreatment of left ventricular tachycardia.

[0026] These and other objects are obtained by the design of the guidingintroducer system disclosed in the instant invention.

SUMMARY OF INVENTION

[0027] The instant invention is a guiding introducer system for use inthe treatment of left ventricular tachycardia from the ventricular side.It may also be used to ablate locations under the mitral valve from theventricular side, for example, for the treatment ofWolff-Parkinson-White syndrome (“WPW”). It is comprised of a precurved,inner guiding introducer and a precurved, outer guiding introducer. Aprecurved dilator is preferably used with the guiding introducer system,which dilator is preferably used with a Brockenbrough needle. The innerguiding introducer is comprised of a first and second section, whereinthe first section is a generally elongated straight section which ismerged at its distal end with the second section, which is a curvedsection. The outer guiding introducer is comprised of a first and secondsections, wherein the first section is a generally elongated straightsection which is merged at its distal end with the second section whichforms a compound curved section. The inner guiding introducer is longerthan the outer guiding introducer to permit it to extend out from thelumen of the outer guiding introducer to form various curves and shapesof the overall guiding introducer system.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028]FIG. 1A is a cross-section of the left side of the heart showingthe placement of the guiding introducer system in the left ventriclewith the distal end of an ablation catheter extending from the distalend of the outer guiding introducer to ablate in three differentlocations along the walls of the left ventricle.

[0029]FIG. 1B is a cross-section of the left side of the heart showingthe placement of the guiding introducer system in the left ventriclewith the distal end of an ablation catheter extending from the distalend of the outer guiding introducer to ablate in two different locationsunder the mitral valve.

[0030]FIG. 2A is a side view of the inner and outer guiding introducersin combination with the distal end of the inner guiding introducerextended from the distal end of the outer guiding introducer.

[0031]FIG. 2B is a side view of the inner and outer guiding introducersin combination as shown in FIG. 2A rotated 90 degrees from the positionshown in FIG. 2A when viewed from the perspective of the proximal end ofthe inner and outer guiding introducers.

[0032]FIG. 3A is a side view of the inner guiding introducer attached toa hemostasis valve and side port with the side port directed to the leftof the inner guiding introducer.

[0033]FIG. 3B is a side view of the inner guiding introducer of FIG. 3Arotated 90 degrees clockwise from the position shown in FIG. 3A whenviewed from the perspective of the proximal end of the inner guidingintroducer.

[0034]FIG. 4A is a side view of the outer guiding introducer attached toa hemostasis valve and side port with the side port directed to the leftof the outer guiding introducer.

[0035]FIG. 4B is a side view of the outer guiding introducer of FIG. 4Arotated 90 degrees clockwise from the position shown in FIG. 4A whenviewed from the perspective of the proximal end of the outer guidingintroducer.

DESCRIPTION OF THE INVENTION

[0036] A typical human heart includes a right ventricle, a right atrium,left ventricle and left atrium. The right atrium is in fluidcommunication with the superior vena cava and the inferior vena cava.The atrioventricular septum separates the atria from the ventricles. Thetricuspid valve contained within the atrioventricular septumcommunicates the right atrium with the right ventricle. The mitral valvecontained within the atrioventricular septum communicates the leftatrium with the left ventricle. On the inner wall of the right atrium,where it is connected with the left atrium, is a recessed portion, thefossa ovalis. Between the fossa ovalis and the tricuspid valve is theopening or ostium for the coronary sinus. The coronary sinus is a largeepicardial vein which accommodates most of the venous blood which drainsfrom the myocardium into the right atrium.

[0037] In the normal heart, contraction and relaxation of the heartmuscle (myocardium) takes place in an organized fashion aselectrochemical signals pass sequentially through the myocardium fromthe atrial to the ventricular tissue along a well defined route whichincludes the His-Purkinje system. Initial electric impulses aregenerated at the sinoatrial (SA) node and conducted to theatrioventricular (AV) node. The AV node lies near the ostium of thecoronary sinus in the interatrial septum in the right atrium. TheHis-Purkinje system begins at the AV node and follows along themembranous interatrial septum toward the tricuspid valve through theatrioventricular septum and into the membranous interventricular septum.At about the middle of the interventricular septum, the His-Purkinjesystem splits into right and left branches which straddle the summit ofthe muscular part of the interventricular septum.

[0038] Sometimes abnormal rhythms occur in the heart which are referredto as arrhythmia. For example, patients diagnosed with WPW have anarrhythmia, the cause of which is believed to be the existence of ananomalous conduction pathway or pathways that connect the atrial muscletissue directly to the ventricular muscle tissue, thus bypassing thenormal His-Purkinje system. These pathways are usually located in thefibrous tissue that connects the atrium and the ventricle.

[0039] Another arrhythmia is ventricular tachycardia (“V.T.”). VT is adisease of the ventricles of the heart in which the heart's normalarrhythmic contraction is altered. Frequently, the rate of heart beat istoo fast, although the conditions of the disease itself are generallyquite complex. VT occurs most often in patients following a myocardialinfarction. A myocardial infarction, commonly referred to as a heartattack, is a loss of blood to a region of the heart causing themyocardial tissue in that region to die and be replaced by an area ofscar tissue known as a myocardial infarct. Frequently, the myocardialinfarct is present in the left ventricle.

[0040] As a result of the myocardial infarct, circular pathways(“reentry circuits”) are frequently created within the left ventriclewhich conduct electrical impulses of the heart. These reentry circuitscause the electrical impulses of the heart to travel in circles aboutthe myocardial infarct, frequently causing an erratic and sometimesaccelerated beating of the heart. These reentry circuits may also occuraround discreet elements of the heart, such as valves. In addition, thereentry circuits sometime occur around both the myocardial infarct andthe discreet elements of the heart.

[0041] In the past arrhythmia have been generally treated by the use ofdrugs, such as lidocaine, quinidine and procainamide. More recently,beta-blocking drugs have been used for this treatment. In cases wheredrug therapy has been ineffective, surgical procedures have sometimesbeen used to excise the tissue causing the arrhythmia. The procedureinvolves the removal of a portion of the heart muscle, particularly thatportion around which the reentry circuit has formed. By the excision ofthis portion of the heart muscle, scar tissue is formed which preventsthe reformation of the reentry circuit. Obviously such procedures arehigh risk, frequently requiring prolonged periods of hospitalization andrecuperation. As an alternative to these procedures, ablation deviceshave been used for the diagnosis and treatment of cardiac arrhythmias.See, for example, U.S. Pat. No. 5,222,501. Also, guiding introducershave been used to guide ablation catheters for the treatment of atrialarrhythmias in U.S. Pat. Nos. 5,497,724 and 5,427,119.

[0042] Ablation procedures, however, are frequently unsuccessful unlessrepeated many times. It is presumed that one reason for the lack ofsuccess of ablation of ventricular tissue is the failure to destroycompletely the reentry circuit in the ventricular tissue because of itsinherent thickness and the size of the reentry circuit itself. Toeffectively ablate the ventricular tissue, the ablation catheter must bepositioned precisely within the ventricle and maintained in contact withthe ventricular tissue throughout the ablation procedure. Suchprocedures may require the ablation electrode of the ablation catheterto remain in contact with the ventricular tissue for a period of timewell over a minute. This is particularly difficult when the heart isbeating, sometimes irregularly, during the entire ablation procedure.Thus, it is critical that the ablation electrode be maintained at thedesired location and also be constrained from movement throughout theablation procedure.

[0043] Historically, there are two approaches to the positioning of anablation catheter in the left ventricle for ablation procedures. Thefirst approach is to introduce the catheter into the femoral arteryusing a standard introducer and advance it up the aorta, across theaortic valve into the left ventricle and then position its electrodeadjacent to a wall of the left ventricle. This is commonly referred toas a “retrograde” approach. This approach is discussed in patentapplication Ser. No. 08/388,800 filed Feb. 14, 1995 and patentapplication Ser. No. 08/389,252 filed Feb. 16, 1995. Specific locationsfor the mapping or ablation of the ventricular tissue, include locationson the lateral freewall, posterior freewall, septal wall and anteriorfreewall. The retrograde approach to the left ventricle for ablationprocedures is frequently difficult for many reasons including thestructure of the left ventricle, the fact that it requires arterialaccess and potential problems associated with ablation of ventricletissue, such as the creation of a substrate for a future arrhythmiawhich could result in sudden cardiac death. Thus, this retrogradeapproach is not preferred.

[0044] A second approach to positioning an ablation catheter fortreatment of arrhythmia located in the left ventricle is from the atrialside of the mitral valve. This approach is referred to as thetransseptal approach as the ablation catheter passes through theinteratrial septum between the right and left atria. In this procedure,a transseptal sheath apparatus, comprising a conventional transseptalintroducer, such as is produced by Daig Corporation, is introduced intothe right femoral vein and advanced through the inferior vena cava intothe right atrium. A puncture is then made through the interatrialseptum, preferably at the fossa ovalis, and the apparatus is thenadvanced into the left atrium where the needle and dilator of theapparatus are removed leaving the introducer in place in the leftatrium. An ablation catheter is then advanced through this introduceradjacent to or through the mitral valve for treatment of variousarrhythmia associated with the left ventricle.

[0045] Mere introduction of the ablation and mapping catheter into theleft ventricle is not sufficient to effectively and efficiently performthe ablation procedures to eliminate arrhythmia located in the leftventricle. The medical practitioner commonly monitors the introductionof the catheter and its progress through the vascular system by afluoroscope. Such fluoroscopes can not easily identify the specificfeatures of the heart in general, and the critically importantstructures associated with the left ventricle in specific, thus makingplacement of the ablation electrode difficult. This placement isespecially difficult as the beating heart is in motion. As a result, thecatheter is moving within the chambers of the heart as blood is beingpumped through the heart throughout the procedure. The guidingintroducer system of the instant invention addresses and solves theseproblems.

[0046] Referring now to FIGS. 1 through 4, the guiding introducer systemof the present invention for procedures in the left ventricle for thetreatment of arrhythmia associated with the mitral valve from theventricular side, such as WPW, and various ventricle tachycardia iscomprised of an inner and outer guiding introducer. See FIGS. 1A, 1B, 2Aand 2B. Each introducer is divided into a first and second sections.(Each section is preferably formed as an integral portion of the entireguiding introducer without discrete divisions. However, the division ofeach guiding introducer into different sections better illustrates theoverall shape of the guiding introducers.) Each of the guidingintroducers will be shown in two views. See FIGS. 3A, 3B, 4A and 4B. Ineach of the views for ease of analysis, the guiding introducer will besecured to a hemostasis valve with side port for attachment toconventional side port tubing and a stop cock. In each such arrangement,the shape of the guiding introducer and each of its sections will bedescribed, making reference to its position in relation to the side portwhich is attached to the proximal end of the guiding introducer.

[0047] The guiding introducer system for use in the left ventricle iscomprised of an inner and an outer guiding introducer. See FIGS. 2A and2B. A dilator is also preferably used, wherein the dilator preferably isa transseptal dilator used with cardiac procedures requiring aBrockenbrough needle for a transseptal puncture. Generally the distalend of the dilator is curved in a curve with an arc of about 20 to about70 degrees ending in its distal tip. The overall length of the dilatoris conventional.

[0048] The inner guiding introducer is generally comprised of twosections. See FIGS. 3A and 3B. The first section is a conventionalgenerally elongated, hollow straight section of sufficient length forintroduction into the patient and for manipulation from the point ofinsertion to the specific desired location within the heart. Merged withthe distal end of the first section of the guiding introducer, but anintegral part of the entire guiding introducer, is the second sectionwhich is a curved section, curved with a radius of about 0.5 to about1.5 in., preferably from about 0.7 to about 1.3 in. and most preferablyabout 0.9 to about 1.1 in. to form an arc of approximately 45 to about135 degrees, preferably about 60 to about 120 degrees, and mostpreferably about 70 to about 110 degrees ending in a distal tip.

[0049] The outer guiding introducer for use in the left ventricle iscomprised of a first and second sections. See FIGS. 4A and 4B. The firstsection is a conventional, generally elongated hollow straight sectionof sufficient length for introduction into the patient and formanipulation from the point of insertion to the specific desiredlocation within the heart. Merged with the distal end of the firstsection of the guiding introducer is the second section which ispreferably a compound curved section curving first in a first curvedportion with a radius of about 0.5 to about 1.5 in., preferably fromabout 1.0 to about 1.4 in., and most preferably about 1.1 to about 1.3in. with an arc of approximately 10 to about 50 degrees, preferablyabout 10 to about 30 degrees and most preferably about 15 to about 25degrees. Following the first curved portion is the second curved portionwhich curves with a radius of about 0.5 to about 1.5 in., preferablyfrom about 0.7 to about 1.3 in., and most preferably about 0.9 to about1.1 in. with an arc of approximately 135 to about 225 degrees,preferably from about 170 to about 210 degrees and most preferably about180 to about 200 degrees ending in the distal tip of the outer guidingintroducer. Preferably, the first and second curved portions aregenerally coplanar, preferably within about 20 degrees of being withinthe same plane. As an alternative to the compound curved section, asingle curved portion may be used wherein the radius of this singlecurved portion is from about 0.5 to about 1.5 in., preferably from about0.8 to about 1.2 in. and most preferably about 0.9 to about 1.1 in. withan arc from about 145 to about 260 degrees, preferably from about 180 toabout 240 degrees and most preferably about 200 to about 220 degreesending in the distal tip of the second section of the outer guidingintroducer.

[0050] While the above described shapes are preferred, the shape of thesections of each guiding introducer of the guiding introducer system maybe modified by use of one or more straight or curved sections as long asthe overall, general shape of each of the guiding introducers isapproximately as described above. In addition, the particular order ofthe curves may be changed as long as the overall curvature of each ofthe guiding introducers delivers the mapping and ablation catheter toapproximately the same location as the guiding introducer system abovedescribed as the preferred embodiment. Further, one or more curves ofthe guiding introducers may be combined or split into additional curvedor curved and straight sections as long as the general overall shape ofthe precurved, guiding introducers is maintained.

[0051] The design feature of the guiding introducer system provides astable platform supported by the cardiac anatomy to permit an ablationor mapping catheter to be advanced and withdrawn without the need forrepositioning the guiding introducer system. By extending the distal tipof the inner guiding introducer away from the distal tip of the outerguiding introducer and by rotating the inner guiding introducer withrespect to the outer guiding introducer, a variety of shapes of theguiding introducer system are formed to direct the mapping and/orablation catheter toward a particular site within the left ventricle.See FIGS. 1A and 1B where the distal end of the inner guiding introduceris rotated and/or extended to permit the ablation catheter containedtherein to ablate various locations within the left ventricle. Theseshapes permit ablation procedures to be performed in the left ventricleassociated with the mitral valve annulus from the ventricular side, forexample, in a position anterior to anterolateral to lateral toposterolateral to posteroseptal to septal to the mitral valve. See FIG.1B. In addition, by adjusting the extension and direction of the innerguiding introducer within the outer guiding introducer, ablation andmapping catheters can be directed for procedures on the left ventricularanterior free wall and toward the septal wall for treatment of BelhassenTachycardia. See FIG. 1A. The various locations can be treated byextending the inner guiding introducer further from the outer guidingintroducer which forms a different overall shape and/or by rotating theinner guiding introducer with respect to the outer guiding introducer.Being able to extend the inner guiding introducer within the outerguiding introducer and to rotate the inner guiding introducer within theouter guiding introducer permits a wide variety of overall shapes, whichis particularly useful to medical practitioners. The medicalpractitioner is able to determine the relative location of the inner andouter guiding introducers because of tip markers located near the distaltip of both the inner and outer guiding introducers.

[0052] The distal tip of both the inner and outer guiding introducersmay be, and generally will be, tapered to form a good transition withthe dilator.

[0053] The relative size of the outer guiding introducer in relation tothe inner guiding introducer should be sufficient to permit the innerguiding introducer to be torqued or rotated within the outer guidingintroducer without undue restriction on such movement. Preferably, thedifference in size between the inner and outer guiding introducer shouldbe at least about 3 “French” (1 French equals about one-third of amillimeter). For example in one preferred embodiment, the outer guidingintroducer is 11 French in size and the inner guiding introducer is 8French. By this difference in diameter, there is approximately 1 Frenchunit of volume available between the outer surface of the inner guidingintroducer and the inner surface of the outer guiding introducer.Preferably, this volume of space between the inner and outer guidingintroducer is filled with a biocompatible solution, such as a salinesolution, preferably a heparinized saline solution. This saline solutionalso provides lubricity to the two guiding introducers, allowing moreaccurate torquing of the inner guiding introducer within the outerguiding introducer. In addition, it is preferable that the structure ofboth the inner and the outer guiding introducer have a high torsionalconstant to allow for the full utilization of the various shapesavailable by rotation and extension of the inner and outer guidingintroducer. To permit this high torsional constant, in one preferredembodiment the inner guiding introducer is braided to provide furtherstrength and structural stability.

[0054] The guiding introducers may be made of any material suitable foruse in humans, which has a memory or permits distortion from andsubsequent substantial return to the desired three dimensional shape.For the purpose of illustration and not limitation, the internaldiameter of the tip of the guiding introducers may vary from about 6 toabout 10 “French” Such guiding introducers can accept dilators fromabout 6 to about 10 French and appropriate guidewires. Obviously iflarger, or smaller dilators and catheters are used in conjunction withthe guiding introducers of the instant invention, modification can bemade in the size of the instant guiding introducers.

[0055] The inner and outer guiding introducers also preferably containone or a plurality of vents near the distal tip of the guidingintroducers, preferably 3 or 4 of such vents. The vents are preferablylocated no more than about 5 to 6 cm. from the tip of the guidingintroducers and more preferably 0.5 cm. to about 4.0 cm. from the tip.The size of these vents should be in the range of about 20 to 60{fraction ({fraction (1/1000)})}of an inch in diameter. These vents aregenerally designed to prevent air embolisms from entering the guidingintroducers caused by the withdrawal of a catheter contained within theguiding introducers in the event the distal tip of one of the guidingintroducers is occluded. For example, if the tip of the inner guidingintroducer is placed against the myocardium and the catheter locatedwithin the inner guiding introducer is withdrawn, a vacuum may becreated within the inner guiding introducer if no vents are provided. Ifsuch vacuum is formed, air may be forced back into the guidingintroducer by the reintroduction of a catheter into the lumen of theguiding introducers. Such air embolism could cause problems to thepatient including the possibility of a stroke, heart attack or othersuch problems common with air embolisms in the heart. The addition ofvents near the distal tip of the guiding introducers prevents theformation of such vacuum by permitting fluid, presumably blood, to bedrawn into the lumen of the guiding introducers as the catheter is beingremoved, thus preventing the possibility of formation of an airembolism.

[0056] Variances in size or shape of the pair of guiding introducers arealso intended to encompass pediatric uses, although the preferred use isfor adult human hearts. It is well recognized that pediatric uses mayrequire reductions in size of the various sections of the guidingintroducers in particular the first section, but without any significantmodification to the shape or curves of the guiding introducers. However,because incremental changes can be made in the overall shape of the pairof guiding introducers, the system can better adjust to differing shapesand sizes of heart than can a single guiding introducer.

[0057] In operation, a modified Seldinger technique is normally used forthe insertion of a catheter into either an artery or vein of the body.Using this procedure, a small skin incision is made at the appropriatelocation to facilitate the catheter and dilator passage. A soft flexibletip of an appropriate sized guidewire is inserted through and a shortdistance beyond a needle which has been introduced into the vessel.Firmly holding the guidewire in place, the needle is removed. Theguidewire is then advanced through the vessel into the right atrium.With the guidewire in place, a dilator is then placed over the guidewirewith the pair of guiding introducers placed over the dilator. Thedilator and pair of guiding introducers generally form an assembly to beadvanced together along the guidewire into the right atrium. Afterinsertion of the assembly, the guidewire is then withdrawn. ABrockenbrough or trocar needle is then inserted through the lumen of thedilator to the right atrium to be used to create an opening through theinteratrial septum, preferably at the fossa ovalis. The tip restsagainst the interatrial septum at the level of the fossa ovalis. TheBrockenbrough needle is then advanced within the dilator to the fossaovalis. After the opening is made through the interatrial septum, theneedle, dilator and pair of guiding introducers are advanced into theleft atrium. After the pair of guiding introducers are advanced throughthe interatrial septum into the left atrium, the Brockenbrough or trocarand dilator are removed, leaving the pair of guiding introducers in theleft atrium. The distal tips of the inner and outer guiding introducersare then advanced through the mitral valve into the left ventricle. Thecatheter to be used for analysis and/or treatment of the ventriculartachycardia or other arrhythmia associated with the left ventricle, suchas WPW, about the mitral valve is then advanced through the lumen of thepair of guiding introducers and is placed at an appropriate location inthe left ventricle. See FIG. 1. By extending and withdrawing the innerguiding introducer from the outer guiding introducer and by rotating theinner guiding introducer within the outer guiding introducer, greatvariances in the overall shape of the guiding introducer system can beachieved.

[0058] By movement of the inner guiding introducer within the outerguiding introducer in conjunction with fluoroscopic viewing, the distalportion of the inner guiding introducer can be manipulated to direct thedistal end of a catheter to a specific internal surface within the leftventricle. See FIGS. 1A and 1B. In addition, by providing sufficientrigidity, the distal end of the inner guiding catheter can be maintainedin that fixed location or surface position of the endocardial structureto permit it to act as a stationary platform for the appropriateprocedures to be performed. If sensing procedures are involved, the pairof guiding introducers are placed in the desired location. At thatpoint, the electrical activity of the heart peculiar to that locationcan be precisely determined by use of an electrophysiology catheterplaced within the guiding introducers and extended from the distal tipof the inner guiding introducer to the surface of the heart. As the pairof guiding introducers permit precise location of catheters, an ablationcatheter may be placed at the precise location necessary for destructionof the cardiac tissue by the use of energy, for example, radiofrequency, thermal, laser or direct current (high energy direct, lowenergy direct and fulgutronization procedures). The precise placement ofthe ablation catheter tip on the cardiac tissue is important as therewill be no dilution of the energy delivered due to unfocused energybeing dissipated over the entire cardiac chamber and lost in thecirculating blood by constant movement of the tip of the ablatingcatheter. This permits a significantly reduced amount of energy to beapplied, while still achieving efficient ablation. Further, time used toperform the procedure is significantly reduced over procedures where noguiding introducers are used.

[0059] It will be apparent from the foregoing that while particularforms of the invention have been illustrated and described, variousmodifications can be made without departing from the spirit and scope ofthe invention. Accordingly, it is not intended that this invention belimited except as by the appended claims.

We claim:
 1. A guiding introducer system for treatment of arrhythmiaassociated with the left ventricle from the ventricular side comprisinga precurved inner guiding introducer and a precurved outer guidingintroducer wherein said guiding introducers are used in combination. 2.The guiding introducer system of claim 1 wherein a dilator containingdistal and proximal ends is used in conjunction with the inner and outerguiding introducers, wherein said dilator curves at its distal end in acurve with an arc of about 20 to about 70 degrees.
 3. The guidingintroducer system of claim 1 wherein the inner guiding introducercomprises a first and second sections each with proximal and distalends, wherein the first section is a generally elongated straightsection, wherein merged with the distal end of said first section is thesecond section which contains a curved section with a radius of about0.5 to about 1.5 in. to form an arc of approximately 45 to 135 degreesending in the distal end of the second section of the inner guidingintroducer.
 4. The guiding introducer system of claim 1 wherein theouter guiding introducer comprises a first and second sections each withproximal and distal ends, wherein the first section is a generallyelongated straight section, wherein merged with the distal end of saidfirst section is the second section which contains a curved portion,curving in a radius of about 0.5 to about 1.5 in. to form an arc ofabout 145 to about 260 degrees, ending in the distal end of the secondsection of the outer guiding introducer.
 5. The guiding introducersystem of claim 1 wherein the outer guiding introducer comprises a firstand second section each with proximal and distal ends, wherein the firstsection is a generally elongated straight section, wherein merged withthe distal end of the first section is the second section, wherein thesecond section contains a compound curved section containing a firstcurved portion and a second curved portion, wherein the first curvedportion has a radius of about 0.5 to about 1.5 inches and an arc ofabout 10 to about 50 degrees and the second curved portion has a radiusof about 0.5 to about 1.5 inches and an arc of about 135 to about 225degrees.
 6. The guiding introducer system of claim 3 wherein a pluralityof vents is provided near the distal end of the second section of theinner guiding introducer.
 7. The guiding introducer system of claim 4wherein a plurality of vents is provided near the distal end of thesecond section of the outer guiding introducer.
 8. The guidingintroducer system of claim 3 wherein tip markers are secured to theinner guiding introducer.
 9. The guiding introducer system of claim 4wherein tip markers are secured to the outer guiding introducer.
 10. Amethod for the mapping and ablation of arrhythmia associated with theleft ventricle from the ventricular side comprising (a) introducing intothe left side of the heart a guiding introducer system comprising aprecurved inner guiding introducer and a precurved outer guidingintroducer, wherein each of the inner and outer guiding introducerscontains a lumen passing therethrough, a proximal end and a distal endand wherein the inner guiding introducer is extended into and throughthe lumen of the outer guiding introducer; (b) introducing into thelumen of the inner guiding introducer a catheter for mapping andablation, wherein said catheter contains a distal tip and one or moreelectrodes; and (c) extending said distal tip of the catheter throughthe lumen of the inner guiding introducer and beyond the distal end ofthe inner and outer guiding introducers to allow the electrodes of thecatheter to map and ablate sites within the left ventricle of the heartfrom the ventricular side.
 11. The method of claim 10 wherein the innerguiding introducer comprises a first and second sections, each withproximal and distal ends, wherein the first section is a generallyelongated straight section, wherein merged with the distal end of saidfirst section is the second section, wherein the second section containsa curved section with a radius of about 0.5 to about 1.5 in. to form anarc of approximately 45 degrees to about 135 degrees ending in thedistal end of the second section of the inner guiding introducer. 12.1The method of claim 10 wherein the outer guiding introducer comprises afirst and second sections each with proximal and distal ends, whereinthe first section is a generally elongated straight section, whereinmerged with the distal end of said first section is the second sectioncontaining a curved section with a radius of about 0.5 to about 1.5 in.to form an arc of about 145 to about 260 degrees, ending in the distalend of the second end of the outer guiding introducer.
 13. The method ofclaim 10 wherein the outer guiding introducer comprises a first andsecond section each with proximal and distal ends, wherein the firstsection is a generally elongated straight section, wherein merged withthe distal end of the first section is the second section wherein thesecond section of the outer guiding introducer contains a compoundcurved section containing a first curved portion and a second curvedportion wherein the first curved portion has a radius of about 0.5 toabout 1.5 inches and an arc of about 10 to about 50 degrees and thesecond curved portion has a radius of about 0.5 to about 1.5 inches andan arc of about 135 to about 225 degrees.